Hello, I think I need to amend my 2019 return. When going through the process, I wrote down that I didn't receive a pay increase, when in fact I did.

Huh?  You enter your W2 exactly as shown.  It will be for your total income for the year.  I don't recall a question asking if you got a raise.  Did you already submit your 2019 return before you got the W2?

There might have been some sort of preliminary "life change" questions that asked if you got a pay raise, but there is nowhere at all to enter that on your actual tax return, so the way you answered is irrelevant.  As VolvoGirl said, you just have to enter your W-2 exactly as it appears and let the software do the calculations.